heart palpitations, tightness in chest, and occasional chest pain?

Hi, I am a female age 20.
I’ve been having heart palpiations (irregular heart beats) for the past 2-3 months. I can feel tightness in chest and palpitations mostly when I am lying down or sitting, especially when lying on my left side. there are occasional small chest pains on the left side of my chest. It just feels like my heart is working real hard to pump blood. Can these symptoms be from anemia, stress, or anxiety??

I have suffered for the last 5-6 yrs of the same symptoms at times, and been to all kinds of docs and it seems it’s anxiety. I found for myself that when I cut back on coffee, things seem to settle down a bit.

Tightness in Chest with Anxiety